Lighting and ignition system



J. H. HUNT LIGHTING AND IGNITION SYSTEM Dec. 4, 1928. 1,693,985

Original Filed Oct. 25, 1924 STOP 87A RT.

Patented Dec. 4, 192 8. i

1,693,985 UNITED STATES, um

JOHN H. HUNT,

LIGHTING AND IGNITION SYSTEM.

Original application: filed October'- 25, 1924; Serial .Ro."745,942. Divided; and this application ,filed Karch 21', @927. serial Nog 177,020; r i

This invention relates to electrical systems for automotive vehicles and particular-ly to apparatus for applying, ignition current for the engine and curr'entfor lighting purposes.

This application is a division of my copending application Serial No. 745,942 filed October 25, 1924.

This invention is particularly adapted'for use on farm tractors and the like which do not generally require electricalstarting 'ap paratus and, consequently, in which the storagebattery is not necessary. I v

In electrical systems which supplycurre-nt for engine ignition andvehicle lightingonly, there is usually providcdone dynamo-electric machine, a magneto,'which furnishes current for.ignition'purposes, and a separate dynamoelectricmachine is provided for furnishing the vehicle with electric lighting. Sometimes the two machines are combined all in one unit, but such a machine has separate fieldsf and separate armatures sothat the unitary structure is in effect two separatedynamoelectric machines. Precautions are. sometimes taken to insulate magnetically the two fields from one another so that the operationof: one

dynamo-electric machine may not affect theoperation of one other in-the unitarystruoture. Whore magnetos are used tosupply ignition current for engines which arelstart'ed by hand, it has been found. necessary 'touse. impulse starters so that the magnetom'ay'be operated. with sufficient rapidity periodically, to supply ignition current while the engine is being'cranked by hand.

It is among the objects ofthe present invention to provide a lighting and ignition system includinga dynamo-electric machine having a permanent magnet field and one rotor for .supplying current both for ignition and for lighting purposes.

It is a further object to provide electrical apparatus for supplying current sufficient for ignition purposes at engine speeds attained by cranking and without the use of van impulse starter drive or couplingbetween the magneto and some engine part operatedby the hand crank. I

A further object is to provide a system of regulation wherein the potential of thelight' ing' current willremain substantially con- .stant over a wide variation of enginespeed; In this CODHGCUOIY 1t is an ob ect to provide regulating circuits infiw-hich: no moving parts A further objectis toiprovide a system of" are required.

control Wherein the supplying of ignition by the dynamo electric-machine does not appreciablyinterfere with the supplyingoflightmg current; i

Other andfurther objects of the present. invention will be apparent from the followor nn'rnorr, MICHIGAN; assrenon ro nnntco nnmy conronarron, I or DAYTON, 01-110, aoonrona'rron or DELAWARE.

ingdescription, reference beinglhad to the accompanying drawings, wherein a preferred form of embodiment of the present invention is clearly shown,

Q In the drawings? The figure ofthe drawingis-a wiring dial gram illustratingthe invention. The generator 30 for supplying: the light ingand gnition circuits of the present invention is disclosed in detail in my co-pending application, Serial No. 576,493, filed October 25, 1924. For understandingthe present: invention it is suflicient tostate that: the gamerator 30 includes a-stationary two pole-permae nentmagnet fieldSl the pole's33-and 34 of which are laminated and eachprovided withpreferably four teethsspaced by slotsfor re cciving pole facewindings. The eight pole teeth (numbered 41 to 48 inclusiveyextend' radially with respect to the armature axis, and are equally spacedi w The dynamo SD -includes an armature 84 which is carried-by a:shaft 76 .whichis operated by an internal combustion: engine 20 at twice engine speed through gearsQland-221 v The armature "core; 84 is laminated? and the cylindrical periphery thereof is nOtClied to provide a series-ofequally spaoedtecth 220,- the face of each tooth being approximately one third the greatest width of the notchbetween adjacent teeth. It is desirable that hand, if the notches are too Wide, the teeth .the notches spacing: the teeth the as wide 220:will be toonarrow to carryefiiciently the flux from the variousjpole teethof the permanent magnets. Satisfactory pro; portions of widthoffnotchto width of arma-.-

ture tooth face have been-found to be from i 4/ 1: to 2.5 1. The notches between certaimof the armature teeth" 220*,- 220i, 220, 220%, 220 andQQO", are made'considerably deeper than other notches in order toprovide for the armature winding, arranged in two coils 221 i and 222 which are wound about armature core 7 84 after theiashion of the ordinary shuttle wound armature windings, and these windings areconnected in series and one end of the group of widings is grounded by a grounded brush 201, and the other end of the group of armature windings is connected by a brush 160 and wire 161 with a timer mechanism and airignition coil to be described; 1 By way of example, the following armature dimensions aregiven to show what proportions having been found satisfactory in one mHChIDECOII- structed'in accordance with the present in ventioni Core length 3 inches. Core diame ter 1.875 inches'f'Twelve core teeth. WVind-- ings 221 and 222 have each 1.00 turns, ofNo; 23 wire. It willbe noted that the magnetic armature windings differ from the ordinary shuttle wound armature windings in that the windings includetwo coils which are sep-' arated the relativelylong armature core teeth 220 and 220 creases the time of duration of the short circuit current in the armature at values continuously above the minimum required for ignition and also reduces the lnductance per turn to a value substantially less than what it would beif the windings were concentrated. Th s arrangement permits a widerrange of adjlustment of the ign tion timer than is pos siblewhere'the armature turns are all concentrated between adjacent core teeth.

ilhe pole'face. windings 231, 232, 233, 234,

' 235, 236, 237, 238 surround the field pole teeth 41 to 48 inclusive, respectively; and, when joined in seriestheir E. M; F.s are cumulative. These windings sup. ly current to the headlamps 291and urrentfor the tail lamp 317 is induced in pole face windings having a length of 3 inches, and a diameter 7 of 1%;inches: winding 232, 233, 234,236,

237; and 238 each have40 turns of No. 17

. wire. Windings 231and235 eachhave 30 turns ofNo. 17 wire. 1Vindings243 and 244 each have 150 turns of No. 27 wire. Anextension 7 6 of the armature shaft 76 carries a timer cam 78 which cooperates with the rubbing blocks 152 and 156 of breaker levers 149 and 154 respectively carrying timer contacts 147 and 148 respectively which en- "a'ge contacts 145'and 14-6, respectively. rings 1'51 and 158 cooperate withthe'levers 149and 154, respectively,to urge the levers toward the cam 78. Numeral indicates a suitable timer housing. or cup which is secured to the dynamo frame in any well known .manner. The shaft76 carries a gear 181 p meshing with a gear183 which operates a shaft '182 carrying a distributor-rotor concondenser 251 is connected in This construction intact 185 which distributes sparking impulses from a centerterminal 194to terminals 192' supportedby a distributor head-189. Ter-. minals 192 are connected with engine spark plugs 256.1 The ratio of gears 181 and 183 is t'ourto one so thatithe rotor185 will rotate at one-half engine speed."

: The wire 161 .connectsthe, armature coils 221 and 222 with the lever 154 which is insulatedl VVirc140 connects the co'ntact146 with contact 145. Contacts 148, 146, and 1.45

are insulated, and'contact 147 is grounded since the lever 149 is grounded upon the timer cup 65. A condenser 250jis connected in shunt with contacts 146 and 148, and a shunt with con tacts'145 and, 147. 3

primary 253 of an ignition coil 252. The

secondary 255 is grounded with coil 253 at A wire 170 connects the wire 140 with the 254, andis connectedby wire 256 with the V rotor contact. 185.

In the drawin includes a switch ever 261 carrying contacts 262and 263 which are-insulated from one another. Contact 2631s connected with the pivot point of the lever 261 which is grounded i l at 264,'a11d contact 263 is arranged to engage stationary contacts 265, 266, or 267. Contact 262 is arranged to connect two stationarv contacts 268 and 269. commence ancient an ignition switch 260 are joined by wire 270;contact 268 is joined it i with magneto terminal 239'by' wire 271; sta

tionary contact 265 is "connectedwith wire 161; contact 266 is connected by wire 272 with magneto terminal 242; and contact 267 p is connected by wire'273with magneto ter; m nal 240. i The externally regulated lighting circuits include, respectively, the group of pole face.

windings 231 to 234 inclusive, having a terminal 239, and the group of pole face windngs to 238 incluslvehaving a 121111111111."

240. These groups of windings have a con imon ground terminal 242; The terminal 239 is connected by wire280witha transformer primary 281 which 1s connected with a switch blade 282 :adaptedto engage with contact 28.3 or to connect contacts 284 and 285. Tor

minal 240 is connected by wire 286with a contact 289 or 290. .Contacts 283 and 285 -are*connected with an electric lamp 291 grounded at 292 and contacts 289511111 296 are connected with anelectric lamp 293 grounded. at 294. Contacts 284 and 289 are connected together through adiminer resistance 295. The transformer primaries 281 and 287 cooperate with transformer second ary windings 296 and 297 which are connectedtogether in series with a condenser 298. Preferably the windings 296 and 297 are grouped togetheron one leg of a magnetic circuit while the windings 281, and 287 transformerprimary 287Iwhich is connected witha switch blade 288adapted to engage tenants:

are mounted upon: another portion ofthe same magnetic circuit.

In the drawing the, lever 261 is shown-in RUN position, but to start the. engine this lever 2.61 is moved into the START position so that the contact 262 will engage contacts 268 and 269'and the contact 263 will engage the contact 267. The poleface windings are now connected in series and altogether in parallel with the magneto armature windings 221 and 222 so as to assist in producing a sparking impulse sufiicient for engine ignition even when the engine is cranked by hand and the magneto armature rotates at'atrelatively slow speed. The'pole face windings are con-- nected up in the following manner with the wire 161' round 264 switchcontact 263. con- ,J 7 Y g.

tact 26, wire 2(3, term1nal 2 10, windings 238 to 231, terminal 239, w1re271, contacts 268, 262, 269,.wire 270, Contact 265 which is connected to the Wire161.

The current wave of the-pole facewind-i ings includes a series of peaks alternating above and below the zero llIlQ; 1n the machine disclosed, during a revolution of the armature, there will be-twelve positive pea-ks alternating with twelve negative peaks, and

the peaks will extend approximately the, same distancefrom the zero line.

' The current wave of the armature, when short-circuited also includes a series of pea z. extendingalternatelyabove and below a certain mean line.- This mean line is not the Zero current line but approximates a sine curve making a complete wave each revolution of the armature. During each revolution of the armature of the machine disclosed there willbe twelve peaks inthearmature current above this mean line alternating with twelve peaks below the mean line. Once'a revolution there is a peak extending above the mean line which has positive value greater than any other of the positive in the armature short-circuit currentwave,

and it happens that this peak occurs substantially in phase with one of. the positlve peaks of the pole face winding current wave.

This coincidence of these particularcurrent wave peaks is takenadvantage of in providing ignition current during slow cranking of the engine. Whenthe pole face windings are connected in parallel with the armature windings invthe manner stated, these two peaks are added to produce a peakevery armature revolution having a current value sufliclent for gnition purposes at engine speeds i produced by hand cranking. After. the er. gino has become self-operativethese maximum positive pears of the armaturecurrent will alone be sufficient for ignition purposes, and half way between maximum positive peaks, there will be a maximum negative peak I sufiicient for engine sparking. Therefore. duriu g each armature revolution.during normal engine running there will be at least two peaks instants when sufficient current. is available 1 speed the, invention is not thus limited, but.

includes magnetos operable at other speeds such asone operatingat engine speed.

. When amagneto ofthe character described operatesat twiceengine speed it is necessary provide a special. breaker mechanism,

which, during the normal running of the engine, will v permit the use of,-only the maximum positive peaks or the maximum negative peaks ofthe armature current wave so that there will be one sparking impulse for each magneto revolution. This will give four impulses for each engine cycle, sufricient for a four cylinder engine. If it isthe maximum positive pea-ks of the armature current wave which assist the pole face 0 rentinproviding starting ignition-the timer is constructed to use only the maximum positive peaks during starting and runningof theengine;

, The cam which operates the breaker levers for controlling rthepair of contacts 14-5, 147 and the pair of contacts 146, 148 is DlOVlClGCl' with two flats located preferably at 150 apart and the breaker levers have their respective camrubbing blocks similarly placed. Each breaker lever closes and opens twice a magnetorevolution, but only once arevolution are both breaker levers closed at thesame time. The. drawing shows the cam 78 in position for opening the lever 154 after lever 1 19 has opened..- The cam 78irotates clockwise asviewed in the drawing. For example,

ice

the home or zero position of the cam may be the instant of opening lever 149. Lever 154 will open at about 15 of cam rotation beyond home position and will close at about 125 and then open at 165 Lever 149will close at about 170 and open at abont210 and will close again at about 320" At about 335 lever 154 will close. Thus, between 335 and 360 both levers will be closed to complete the short circuitof the armature coils 221 and 222 once each revolution of the magneto and four times for each cycle of the four-stroke cycle four cylinder engine 20 The lever maximum positive armature short-circuit currentpeak, in order that a sparking 11n pulse will be produced in the coil 252; The

distributor contact 185 will conduct this-impulse to one of the engine spark plugs 256. The armature coils Wlll remain open circuited from 15 to about125 and. fr0rn'165 to 330. 1 It is ,desi'rable 'to keepf the {armature v1 19 opens substantially at the instant of the g 1 by the opening of the lever154 at 165, no

ignition will then be supplied to the engine since the distributing rotor is about midway between the distributor contacts 192. v The closing and opening oft'he breaker lever 149 at 170 and 210, respectively, will have no effcctsince the lever 154 is then open, The lever 149 is closed at 320? from home position in order that, when the lever 1 54closes at the sl'iort-cireuit of the armature coils 00;.) will then be completed. As stated before,

i when the lever149opens at the end of the magneto cycle or at 360 from home position,

a sparking impulse will be produced in the V The opening of the transformer coil 252. lever 154 at 15 following the opening of the lever 149 causes the armature circuit to be interrupted as soon practicable after the sparking impulse has been generated.

After the enginefbecomes self-operative the speedof the magneto will be such that the value of themaximum positive peak of the armature current wave will besuflicient for ignition purposes. The Wave form for the.

pole face winding current will remain substantially the same but the height of the. peaks willtend to increase with increasing engine speed. Regulation of the lighting cirlevers would be closed at the same time. The

levers would be arranged so that the ground- 7 cuit hmvcver iseflected in a maner to be described.

If, forexample, the'magneto be one con-' structed to. operate at engine speed, and fire a-four cylinder engine exploding at equal 1ntervals, then the'timer would be constructed to use the maximum positive peak and maxi mum negative peak every magneto revolution so that there would be four sparking impulses for each engine cycle for a four-strokecycle engine. The timer cam would have the flats located 180 apart and the breakerlevers arranged sothat twice a revolutionboth ed breaker 149 would open slightly 'aheadof the breaker 154 in order to maintain the armature open circuited' as long as possible. It is to be understood also that the present invention is not limitedto ignition for a four cylinder four-stroke-cycle engine, but can be applied to ignition for other multicylinder engines with such changes as will be apparent to those skilled in the art.

The dividing of the armature windings into two coils 221 and 222separated by core teeth results inthe inaximum'positive arma-f ture current peaks being of such a shape that for a relatively great proportion of the duration of the wave peak, the' peak is at values 7O greaterthan theminimum required for ignition purposes. Therefore, although "the breaker lever rubbing block may wear into a difierentshape and tend to change the igni-.

tion timing, a certain variation is permissible because of the character of thewave peak just described. i

After the engine has become self-operative the lever 261 is moved into RUN position shown in the drawing. If the levers 282 and; 288 are in BRT (bright) f position in the drawing, one of the externally regulated cir cuits will be as'follows: ground 264, switch 263, contact 266, wire 272, terminal 242, pole facewindings 234,233, 232, and 231, terminal 239,-wire280,transformer primary 281, lever 282, contact 283,- lamp 291, and ground 2 92.

The other externally regulated circuit will i be asfollowszground 264, switch 263, con

tact 266, wire 272, terminal 242, pole face 1 r windings 235, 236, 237 and 238 terminal 240, wire 286, transformer primary 287, lever 288, contact 290,1a1np 293 and ground 294. The

coils 231 to 238 which were connected to gether in series to serveas an ignition booster clrcult are now d vlded lnto-two groups by 1y, group of coils'231 b01234, inclusive, for, supplying current to lamp 291, and group'of coils 235 to 238, inclusive, for supplying current to lamp 293. r a w 7 v The function of the-circuits including the transformer windings 281, 296 and 287, 297, and the condenser 298 is to regulate the volt age of the lighting circuits. This is er;-

plained in detail in'my cope'nding applicw 10:.

tion Serial N 0. 745,942.

To stop the engine, lever-261 is moved to STOP position wherein the contact 263 en-v gages contact 265 and the armature is short circuited. I I

The follow ngadvantages are present in this invention:

The generating unit, provides current for lighting and current for Ignition by the use of but one magnetic circuit-and source of'115 magnetismand one set of rotating windings." The magnets and armature cooperate to provide ignition current, and pole face windings and the armature teeth orinduotor poles cooperate as a high frequency A. C. generator to produce lighting current. l

f In high frequency A. C. machines, it has beenthe practice to employ more stator slots than inductor poles,but such practice could.

not be employed in the present invention as the winding space would be insufficient. Also the available flux is limit cdwhere permanent magnets aregused. 'In the large inductor alternatormoreflux is available 1n proportion than in a small magneto because the field 4 0.3 the common grounding terminal 242, 'namei rotor tooth be followed ina small unit using permanent magnets the stator Winding space will be insuflicient. This difficulty een overcome byomitting t-wo'out of every three stator teeth and increasing the cross'section of the remaining teeth in order to carry the flux. For example, starting with a construction involving 24- stator teeth and 1:2 rotor teeth, the number of stator teeth was reduced to 8 while preserving the same frequency for a given engine speed, and resultingin'three times the available winding space and approximately threetimes the output. This 2 to 3 ratio and the use of 12 rotor teeth has been found to give a frequency which is satisfactory from a lighting viewpoint and also for nherent external regulation by means of a resonant circuit. A two to five ratlo could be 7 employed, such as 4 stator teeth to 10 rotor teeth, but the frequency and hence the potential might be too'low unless machine be operated at a higher speed. An 8 to 20 combination could be used provided the diameter of the armature is large enough to permit a rotor tooth of sufficient. width to carry the flux, it being borne .in mind that the rotor tooth spaces must be great enough to prevent flux leakage and the consequential inefliciency of the machine. Either combination of 8 to 12 or 8 to 20 or 4 to 10 (the 2 to 3 ratio or the 2 to 5 ratio) is possible depending on operating conditions and size. It is to be remembered that the number of rotor teeth should be divisible by half of the number of stator teeth so that the pulsations of flux from thepermanent magnets will be minimized.- In the combinations of stator and rotor teeth men-. tioned, it is apparent that there will be a line up of rotor teeth with stator teeth'for'every angular movement of the rotor" through angle of 360 degreesdivided by twice the number of rotor teeth and the number of line-ups will remain constant. Since the line-ups cornefat regular intervals and are constant in number, these other advantages just'mentioned will result; Of course it is necessary to minimize flux pulsations in the magnet in order that the magnetism may be retained for a longperiod. T v 7 By employing a double slottediarmature instead of a single winding slot as in the ordinary shuttle armature the form of ignition current Wave is improved and the inductance per turn of armature winding 1s reduced, also improving ignition.

Satisfactory ignition isprovided throughout the entire range of driving speeds and even at lowspeeds preVailing'du-ring crank- 'ing'the engine'by hand, Without theuse of an impulse coupling. This is accomplished by using the pole face windings to assist the armature windings during startingi The armature circuit is established practically only needed for ignition purpose'sby 'mea'n's of the double breakersmechanism, so

that armature reaction causing a demagneti'-' zatlon of the permanent magnets 1s reduced to the HRHHHIUID. I i

When one of the lamps'291 and- 293 out the remaininglainp will burn with substantially the same intensity as before}: Ob-

viously more independent lamp circuits may "be provided for by adding a group of pole face windings for each additional circuit."

Regulation of the lighting circuits hasbeen accomplished Without the use of moving arts, i Whilethe headlamp circuit iscalledanex ternallyregulated circuit, and the tail lamp.

circuit an externally unregulated circuit, it

is to be understood thatas to both circuits the magneto pole face windings have some inhereentregulation. In thecase of the windings; f supplying current for the tail lamp, the num-:"

ber of turns per pole tooth is great enough and the inductance high enough for inherent regulatlon. Therefore, an external regulator has not been found necessary. As the size of the machine is limited it is not practical to increase the turns per pole of the windings of the head lamp circuit to an amount sufficient for inherent regulation.

While the form of mechanism herein shown and described constitutes a preferred form of embodiment ofthe invention, it is to be understood that other forms might be adopted, all coming within the scopefof the claims which follow. I

What is claimed is as follows 1. An electrical system comprising, in combination, a. generator having a permanentmagnet field and windings for generating ignition current; an ignition transformer coil; acircuit paralleling thetransformer coil and including a circuit breaker; a cir.- cuit including a: circuit-breaker. connecting the generator wlndings with said 0011 and paralleling circuit; and engine operated i means for controlling the circuit breakers in order that, at acertain time, both breakers be I in circuit closing position, that thefirst break er will open whilethe secondfbreaker remains I closed, and'that the s'econdbreaker will open after the first breaker has opened, for the purpose specified. r 1

2. An electrical bination, a generator having a permanent ,magnet field, win-dlngs for the generation of system comprising, in com- 5 12 I" ignition. current, and means for causing the :1

generation of current in said. windingsand including an engine driven shaftoperatedat a speed twicethat required for the'productionf "-Of the number of ignition current peaks necessary for ignition purposes; an ignition.

, transformer coil;'and ignition timing means bination, a generator having a permanent 'magnet'field, windings for the generation of including a cam on said shaft and circuit breaking devices operated by the cam for ignition current, and means for causingtlie eneration of current in said windings and including an engine driven shaft operated at a speed twice thatrequired for the production of the number of ignition currentpeaks neces} sary forignitlon purposes; an ignition trans former coil; and ignition tuning meansm- I 25 paralleling the coil, and a circui'tbreakerloit eluding a circuitbreaker located in a circuit cated in acirc-uit for connecting the generator windings With thecoil and parallel circuit,

and a cam on said shaftfor producing the following recurrentserles of operations ofthe circuitbreakers: The opening and closing of r the second breaker whilethe first breaker is open, the opening and closing of the first breaker while the secondbreaker is open, the

closing of the first breaker, the closing; oft-he second breaker while the first breaker is closed, the opening of the first breaker While the secondbreaker is closed, the opening ofthe second breaken' a a v H v In testimony whereof I hereto affix my sig:

nature. a a Q- JOHNH. HUNT.@ 

